The State of California administered a disability insurance system that paid benefits to persons in private employment who were temporarily unable to work because of a disability not covered by workman’s compensation. The program received no state funding but was instead funded entirely by contributions of one percent of the wages of participating employees. Aiello (plaintiff) and other women suffered disabilities resulting from pregnancies. Aiello brought suit in federal district court against Geduldig, a director of the California Department of Human Resources Development, and the State of California (defendants) to challenge the constitutionality of the disability insurance program. Aiello argued the program violated the Equal Protection Clause because, in defining disability, the program excluded from coverage certain disabilities resulting from pregnancy. The district court held that the insurance program was unconstitutional. Geduldig appealed to the United States Supreme Court.